Although applicable to any micromechanical gradient sensors, the present invention as well as its underlying problem are explained with respect to a gradient sensor which is manufacturable using the technology of silicon surface micromechanics.
Generally, gradient sensors can have many uses in the consumer goods and construction industries, for example, in self-adjusting spirit levels, self-adjusting construction lasers, zero-stable gravitational acceleration sensors for monitoring structures (bending of bridges, gradient of buildings, etc.), or, generally, in the alarm technology, for example, in vehicles such as ships, passenger cars, rail vehicles, or aircraft.
Described in the related art are micromechanical acceleration sensors having capacitive comb patterns. However, these cannot sense their own static orientation in the gravitational field, but only measure changes of their position in the gravitational field. However, these changes can only be determined if they take place within a certain time. Slower changes cannot be easily distinguished from operating point drifts which are typical of conventional sensors.
In the known approaches above, it has turned out to be a disadvantage that an extremely slow change, for example, during a bending of a support due to material fatigue, cannot be distinguished, for example, from a temperature-contingent zero drift.